Platelet-Rich Plasma Gel Matrix (PRP-GM): Description of a New Technique

Abstract

Several musculoskeletal conditions are triggered by inflammatory processes that occur along with imbalances between anabolic and catabolic events. Platelet-rich plasma (PRP) is an autologous product derived from peripheral blood with inherent immunomodulatory and anabolic properties. The clinical efficacy of PRP has been evaluated in several musculoskeletal conditions, including osteoarthritis, tendinopathy, and osteonecrosis. When used in combination with hyaluronic acid (HA), a common treatment alternative, the regenerative properties of PRP are significantly enhanced and may provide additional benefits in terms of clinical outcomes. Recently, a new PRP-derived product has been reported in the literature and is being referred to as "plasma gel". Plasma gels are obtained by polymerizing plasmatic proteins, which form solid thermal aggregates cross-linked with fibrin networks. Plasma gels are considered to be a rich source of growth factors and provide chemotactic, migratory, and proliferative properties. Additionally, clot formation and the associated fibrinolytic reactions play an additional role in tissue repair. There are only a few scientific articles focusing on plasma gels. Historically, they have been utilized in the fields of aesthetics and dentistry. Given that the combination of three products (PRP, HA, and plasma gel) could enhance tissue repair and wound healing, in this technical note, we propose a novel regenerative approach, named "PRP-HA cellular gel matrix" (PRP-GM), in which leukocyte-rich PRP (LR-PRP) is mixed with a plasma gel (obtained by heating the plasma up) and HA in one syringe using a three-way stopcock. The final product contains a fibrin-albumin network entangled with HA's polymers, in which the cells and biomolecules derived from PRP are attached and released gradually as fibrinolytic reactions and hyaluronic acid degradation occur. The presence of leukocytes, especially monocytes and macrophages, promotes tissue regeneration, as type 2 macrophages (M2) possess an anti-inflammatory feature. In addition, HA promotes the viscosuplementation of the joint and induces an anti-inflammatory response, resulting in pain relief. This unique combination of biological molecules may contribute to the optimization of regenerative protocols suitable for the treatment of degenerative musculoskeletal diseases.

Keywords: autologous biomaterials; hyaluronic acid; orthopedics; platelet-rich plasma; regenerative medicine.

Figure 1

Processing of the LR-PRP. (A) Separation of the blood components, resulting from the first centrifugation; (B) Collection of the plasma and buffy coat; (C) Plasma and buffy coat, added in another falcon tube; (D) Buffy coat-containing pellet after the second centrifugation; (E) Twenty percent of the bottom layer, representing the LR-PRP; (F) Homogenized LR-PRP.

Figure 2

Heat-induced plasma gel formation.

Figure 3

Obtaining the PRP–HA cellular gel matrix. (A) Syringes containing the plasma and buffy coat; (B) Plasma being heated up to 70 °C for 15 min; (C) The plasma gel; (D) The cooling device; (E) The buffy coat, plasma gel, hyaluronic acid, and three-way connector before mixing; (F) Mixing of the buffy coat with the plasma gel.

Figure 4

Last step before infiltration. (A) The mixed buffy coat and plasma gel are homogenized with hyaluronic acid to obtain the PRP–HA cellular gel matrix; (B) The final product, ready for use.

Figure 5

Illustrated chart representing the method for obtaining the PRP-GM. (1) PRP is prepared as previously described [10]; (2) The collected plasma is heated up to 70 °C for 15 min in order to form a gel; (3) The plasma gel and buffy coat are mixed into a syringe; (4) Hyaluronic acid is added to the mix; (5) Schematic illustration of all of the components present in the PRP-GM.